109 — Air in boiler circuit (temporary fault)

What does 109 mean?

There is air trapped within the boiler's heating circuit, which can interfere with water circulation and heating efficiency. This is often a temporary issue.

• Air bubbles in the system after filling or maintenance
• Pump not operating correctly
• Issues with pump power input wiring

Click steps to track your progress.

1. 1

   Press and hold down the Reset button for 2 seconds to try clearing the fault.

2. 2

   Check the system pressure and top up if necessary as per the 'FILLING THE SYSTEM' section.

3. 3

   Bleed any radiators in the system to remove trapped air. Start with the lowest radiator and work your way up.

4. 4

   If the fault persists, contact an Authorised Service Centre to check pump operation.